1) Development of non-invasive imaging in the pregnant mouse abdomen to phenotype mutant mouse embryos with cardiac dysfunction. The team of two pediatric cardiologists and basic scientists in the lab has developed the Visualsonics Vevo 2100 ultra-high-frequency imaging platform to evaluate cardiac anatomy, function and rhythm in wild-type and Phox2b-/- mutant embryos lacking autonomic nervous system (e.g. sympathetic and parasympathetic nerves). We have demonstrated abnormal cardiac functions such as irregular cardiac rhythms in Phox2b-/- mutant embryos (Mokshagindam et al. Under Review). In a similar line of experiments, we are using a combination of tissue-clearing method and high-resolution whole-mount imaging to examine what happens to the myocardium development and conduction system architecture in Phox2b-/- mutant embryos. These studies will provide insights in understanding what causes sudden fetal cardiac death in the mutants. 2) Sympathetic control of cardiomyocyte differentiation and maturation. We have developed a 3D co-culture system of iPS-derived cardiomyocytes with sympathetic neurons, endothelial cells, and epicardial cells, and have discovered that the co-cultured cardiomyocytes improve structural and gene expression properties. We are currently attempting to set up the photo-activated regulation of intracellular cAMP for the adrenergic signaling pathway in sympathetic neurons and to examine whether sympathetic activation affects cardiomyocyte maturation. These studies will provide a mechanistic framework for the functional consequence of sympathetic innervation in the developing heart.